Sem 1 Formative Flashcards
Regarding the dehydration synthesis reaction used to form biological polymers, it:
A. Is a type of hydrolysis reaction
B. Liberates energy
C. Requires the addition of a water molecule
D. Involves the loss of a hydroxyl group from one reactant
D. Involves the loss of a hydroxyl group from one reactant
Regarding water, which of the following statements is TRUE:
A. Hydrogen bonding allows water to be a good solvent for non-polar molecules
B. Ionically bonded substances dissolve poorly in water
C. Hydrophobic forces ensure the dissolution of proteins in water
D. Non-polar molecules can act to inhibit surface tension
D. Non-polar molecules can act to inhibit surface tension
A chiral carbon is a carbon that:
A. Forms a double bond
B. Contains a single functional group
C. Contains symmetrical functional groups
D. Cannot be superimposed on its mirror image
D. Cannot be superimposed on its mirror image
Proteoglycans are:
A. Heavily glycosylated glycoproteins
B. Also known as glucosaminoglycans
C. Polymers of glucose
D. A form of mucopolysaccharide
A. Heavily glycosylated glycoproteins
Glycogen is:
A. A polymer of beta-glucose
B. A type of glycoprotein
C. Structurally similar to amylopectin
D. The main storage polymer in plants
C. Structurally similar to amylopectin
A triglyceride is produced when:
A.Glucose and fatty acids combine by a condensation reaction
B. Glycerol and fatty acids combine by hydrolysis
C. Glucose and fatty acids combine by hydrolysis
D. Glycerol and fatty acids combine by a condensation reaction
D. Glycerol and fatty acids combine by a condensation reaction
In animal cells, steroids are derived from the cyclisation of:
A. Cholesterol
B. Lanosterol
C. Cholecalciferol
D. Squalene
D. Squalene
Which of the following amino acids is most likely to be found on the cytosolic face of a protein:
A. Tyrosine
B. Tryptophan
C. Methionine
D. Leucine
A. Tyrosine
Which of the following motifs is the most common way to connect four adjacent anti-parallel β-strands:
A. Up and down β-barrel
B. Zinc finger
C. Greek key
D. Coiled coil
C. Greek key
A purine is:
A. An imidazole ring fused to a furan ring
B. A pyran ring fused to a pyrimidine ring
C. A pyrimidine ring fused to an imidazole ring
D. An imidazole ring fused to a pyran ring
C. A pyrimidine ring fused to an imidazole ring
Which of the following statements is CORRECT:
A.In DNA, thymine and adenine are linked by 3 hydrogen bonds
B. DNA strands are antiparallel
C. Complementary DNA strands have symmetric ends
D. DNA strands are read in the 3’ to 5’ direction
B. DNA strands are antiparallel
Regarding tRNA, which of the following statements is CORRECT:
A. It contains a nucleotide triplet known as a codon
B. It is mature when a poly-A tail is attached to the 3’ end
C. An amino acid can be attached to it via a beta N-glycosidic link
D. Intramolecular base pairing gives it a cloverleaf shape
D. Intramolecular base pairing gives it a cloverleaf shape
Phosphorylated 7-methyl guanosine:
A. Provides mRNA with a tail to prevent mRNA degradation
B. Is removed from pre-mRNA by guanyltransferase
C. Is found on the 5’ end of mature mRNA
D. Inhibits translation
C. Is found on the 5’ end of mature mRNA
Which of the following statements correctly describes the induced fit model of enzymes:
A. The enzyme changes its shape slightly as it binds to the substrate
B. The substrate is altered so that it is induced to fit in the active site
C. The enzyme is altered so that it is induced to fit many different types of substrate
D. Several sites on an enzyme can be induced to act on a substrate
A. The enzyme changes its shape slightly as it binds to the substrate
Checkpoints are found between which of the following cell cycle stages:
A. G1/G0 and G2/M
B. G1/S and G2/M
C. G1/S and G0/S
D. G1/G0 and G0/S
B. G1/S and G2/M
Which of the following statements is TRUE:
A. Methylene blue stains cytoplasmic lipids dark blue
B. Eosin stains the cytoplasm red
C. Haematoxylin stains nuclear proteins red
D. Leishman’s stain is a mixture of haematoxylin and eosin
B. Eosin stains the cytoplasm red
Select the anti-codon corresponding to the DNA triplet sequence TGA
A. ACU
B. ACT
C. UGA
D. TGU
C. UGA
Why? Because the DNA sequence is TGA, the mRNA sequence would be ACU and, therefore, the anti-codon would be UGA
What process exports materials from cells using vesicles?
A. Exocytosis
B. Symport
C. Pinocytosis
D. Antiport
A. Exocytosis
The process used by polar molecules too large to pass through ion channels to traverse the membrane along their concentration gradient is
A. Simple diffusion
B. Facilitated diffusion
C. Osmosis
D. Primary active transport
B. Facilitated diffusion
Select the correct part of the microscope that requires manual adjustment to alter the magnification of an image
A. Fine focus
B. Stage
C. Nosepiece turret
D. Base
C. Nosepiece turret
Select the correct part of the microscope that is used to support the specimen under investigation
A. Condenser
B. Coarse focus
C. Fine focus
D. Stage
D. Stage
The glycocalyx surrounding cell membranes is formed by:
A. Phospholipids
B. Oligosaccharides
C. Peripheral proteins
D. Cholesterol
B. Oligosaccharides
Clathrin coated pits are needed in:
A. Pinocytosis
B. Phagocytosis
C. Exocytosis
D. Endocytosis
D. Endocytosis
Desomosmes use which of the following receptor types as linker protein filaments?
A. Cadherin receptors
B. G protein coupled receptors
C. IgG receptors
D. Tyrosine kinase receptors
A. Cadherin receptors
GLUT receptors transport glucose into cells by which of the following processes:
A. Channel mediated diffusion
B. Carrier mediated diffusion
C. Primary active transport
D. Direct antiport
B. Carrier mediated diffusion
Which protein is found in micro- filaments?
A. Actin
B. Tubulin
C. Vimentin
D.Keratin
A. Actin
A major job of the smooth endoplasmic reticulum is:
A. Storing ATP
B. Produces proteins
C. Folds proteins
D. Produces steroid hormones
D. Produces steroid hormones
How many centrioles are present in a centrosome:
A. 2
B. 1
C. 4
D. 9
A. 2
Which of the following synthesises cytosolic proteins:
A. Rough endoplasmic reticulum
B. Ribosomes
C. Smooth endoplasmic reticulum
D. Golgi apparatus
B. Ribosomes
Tay sachs is a disease of the:
A. Microsomes
B. Proteasomes
C. Peroxisomes
D. Lysosomes
D. Lysosomes
Kinases are an example of which type of enzyme?
A. Isomerases
B. Ligases
C. Transferases
D. Hydrolases
C. Transferases
An enzyme with its cofactor is called a/an:
A. Coenzyme
B. Apoenzyme
C. Holoenzyme
D. Isoenzyme
C. Holoenzyme
Enzymes which form double bonds in an elimination reaction are:
A. Ligases
B. Hydrolases
C. Oxidoreductases
D. Lyases
D. Lyases
Hexokinase has a low Km, this means that:
A. It is inhibited by low levels of substrate
B. It is inhibited by high levels of substrate
C. It is activated by high levels of substrate
D. It is activated by low levels of substrate
D. It is activated by low levels of substrate
Disulfiram (Antabuse) is an example of a/an:
A. Non-competitive inhibitor
B. Competitive inhibitor
C. Uncompetitive inhibitor
D. Irreversible inhibitor
B. Competitive inhibitor
Which of the following inhibitor types reduces Km and Vmax:
A. Non-competitive inhibitors
B. Competitive inhibitors
C. Uncompetitive inhibitors
D. Reversible inhibitors
C. Uncompetitive inhibitors
Enzymes are not regulated by:
A. Gene expression
B. Low substrate level inhibition
C. End product inhibition
D. Phosphorylation
B. Low substrate level inhibition
Which correctly describes the sequence of the cell cycle:
A. Telophase, prophase, metaphase, anaphase
B. Prophase, telophase, metaphase, anaphase
C. Telophase, metaphase, anaphase, prophase
D. Prophase, metaphase, anaphase, telophase
D. Prophase, metaphase, anaphase, telophase
During non-competitive inhibition of enzyme reactions, an allosteric inhibitor binds to:
A. The active site, thus preventing substrate attachment at the same site
B. The substrate, thus preventing the substrate from attaching to the active site
C. The active site, causing a change in enzyme shape
D. A site away from the active site, causing a change in enzyme shape
D. A site away from the active site, causing a change in enzyme shape
Anaphase is characterised by:
A. The nuclear envelope reforms around the chromatin mass
B. The growing spindle pushes centrosomes to opposite poles
C. Chromosomes undergo maximum coiling
D. The kinetochore of each chromatid splits
D. The kinetochore of each chromatid splits
The functional group(s) associated with peptide bond formation is/are:
A. Amine and carboxylate
B. Carbonyl and carboxylate
C. Carbonyl and amine
D. Amine only
A. Amine and carboxylate
During mitosis distinct chromosomes first become visible in:
A. Interphase
B. Telophase
C. Anaphase
D. Prophase
D. Prophase
Which of the following is important to initiate cell growth:
A. Cyclin dependent kinases-cyclin complexes phosphorylating Rb protein
B. Cyclin dependent kinases activating cyclins
C. E2f dissociating from Rb protein, allowing Rb to be activated
D. P53 and p21 up regulating cyclin levels
A. Cyclin dependent kinases-cyclin complexes phosphorylating Rb protein
Taxanes, such as paclitaxel, arrest the cell cycle in which ONE of the following phases:
A. G1
B. G2
C. M
D. S
C. M
The dynamic range of a spectrophotometer lies between the:
A. Limit of quantification and limit of linearity
B. Limit of detection and limit of linearity
C. Limit of detection and limit of quantification
D. Limit of quantification and limit of range
A. Limit of quantification and limit of linearity
In cell microscopy, haematoxylin is commonly used in combination with eosin and acts as a:
A. Wash
B. Fixative
C. Counterstain
D. Destaining agent
C. Counterstain
Which of the following statements is CORRECT:
A. KM tends to vary for a particular enzyme and substrate under defined conditions of pH and temperature
B. A high KM indicates a low affinity of an enzyme for a particular substrate
C. The KM of an enzyme for a substrate is normally lower than the intracellular substrate concentration
D. The KM of an enzyme for a particular substrate is independent of Vmax
B. A high KM indicates a low affinity of an enzyme for a particular substrate
Infusion of a hypotonicsolution reduces cerebral oedema by:
A. Diffusion
B. Osmosis
C. Pinocytosis
D. Active transport
B. Osmosis
Which of the following is NOT a problem of electron microscopes:
A. The electron beam is scattered by air molecules
B. Specimens must be very thin
C. They have a low resolving power
D. Specimens are usually transparent to electrons
C. They have a low resolving power
Which of the following could be used to visualise the actin cytoskeleton:
A. Immunostaining
B. Eosin
C. Methylene blue
D. ELISA
A. Immunostaining
